Universal bending machine

ABSTRACT

AN APPARATUS FOR BENDING STRUCTURAL MEMBERS TO ANY DESIRED ANGLE WITHOUT DISTORTION OF THE MEMBER, COMPRISING OPOSING PAIRS OF BENDING DIES RESILIENTLY MOUNTED RESPECTIVELY ON A FIXED BED AND A MOVING RAM.

J'm 5, 1971` A. T; KAPUSTIN UNIVERSAL BENDING MACHINE Filed Jan. l5, 1968 Sheets-Sheet l Alexana/er 7.' Ka/ousin Jan. 5, 1'971, A. T. KAPUSTIN UNIVERSAL BENDING MACHINE l Filed Jan. l5, 1968 2 Sheets-Sheet 2 NVLN'I'UR /exander 7.-/(2/00527/7 United States Patent() 3,552,179 UNIVERSAL BENDING MACHINE.

Alexander T. Kapustin, Oakland, Calif., assigner to Bethlehem Steel Corporation, a corporation of Delaware Filed Jan. 15, 1968, Ser. No. 697,851 Int. 'Cl. B21d 7/00 U.,S. Cl. 72-389 2 Claims ABSTRACT F THE DISCLOSURE An apparatus for bending structural members to any desired angle without distortion of the member, comprising opposing pairs of bending dies resiliently mounted respectively on a iixed bed and a moving ram.

BACKGROUND OF THE'. INVENTION This invention relates generally to metal bending machines and more particularly to apparatus for bending structural members, e.g., angles, channels, I-beams, etc.

The design of some transmission towers requires bends in the legs and cross-arms of the structure. One such design, for example, -requires the four legs to be bent at the waist and the cross-arms to be bent with one flange in tension and one ange in compression. There are numerous other applications that will come to the mind of the reader where structural members require a bend to fit into the required geometric pattern of the fabricated structure.

Apparatus is known whereby a die block mounted on a movable ram cooperates with a xed die block to engage a workpiece therebetween to effect a bend of previously selected limit. The apparatus, however, requires a change of die blocks for each |variation of bend desired. The apparatus furthermore lacks positive control of the workpiece resulting in buckling in the bend area, necessitating swaging and straightening of the work. 'I'he uniformity of the material in the bend area varies considerably due to buckling, swaging and loose bends. Consistently uniform bends are unobtainable in an operation where a plurality of units are being bent. The tendency of the compression side of a section bein-g bent to buckle and build up excess material creating a wavy surface will be readily understood by those skilled in the art. It is ditlcult to control or prevent such buckling or warping.

SUMMARY OF THE INVENTION The primary object, therefore, of the present invention is to provide a universal bending machine having a novel arrangement and construction of dies by means of which structural members can be bent to a desired shape rapidly and eiliciently.

Another object of the present invention is to provide apparatus for bending angles, channels, I-beams, strips, bars and similar objects and more specically to bend such objects of different sizes with one standard form or die.

A further object of the invention is to provide a bending machine in which a plurality of members are successively bent to the same desired angle after the initial setup.

A still further object of the invention is to provide a bending machine which preserves the cross-sectional shape of the structural member.

To accomplish these objects, the present invention provides apparatus of unique design and construction for effecting an accurate, uniform bend in a structural member resulting in a product which is free from distortion. The apparatus comprises a novel arrangement of die ice blocks which are adapted to clamp the workpiece firmly between opposing pairs of dies while a nose block mounted on the pressure ram of the machine bends the workpiece to the desired shape.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a schematic plan view of the apparatus prior to operation;

FIG. 2 is a schematic plan view similar to FIG. 1 showing the opposing dies engaging a workpiece;

FIG. 3 is a schematic plan view showing the completed bending cycle; and

FIG. 4 is a side view of the apparatus as shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT It will be appreciated that many of the component elements of the universal bending machine of the instant invention are not illustrated in the drawings, their disclosure being unnecessary for an understanding of the present invention. Referring now to the figures and particularly to FIGS. l and 2, the bending machine 10 is seen to comprise a conventional hydraulic press having a first housing 11 and second housing 12 mounted respectively on the movable press ram 13 and press bed 14 dening a parting line 32 therebetween. A nose block 22 is xedly mounted on ram 13 at the center of housing 11 extending toward the parting line 32. Mounted within each of said rst and second housings are pivoted die support members. The first pair 16 of die support members mounted in the irst housing 11 on opposite sides of the nose block and in abutting relationship thereto are pivotally mounted for rotation about axes spaced outwardly of the nose block and rearwardly of the parting line, i.e. between the ram 13 and the parting line 32, and adapted to be guided around the tip of said nose block during the bending operation.

The second pair 17 of die support members carried in the second housing 12 at the center thereof are connected to each other by a transverse hinge 18 on the center line of the machine in alignment with said nose block. Trans- Verse pivots 19 mounting the second pair of die support members 17 in the second housing 12 provide for rotation of the second die support members 17 about axes spaced outwardly of the hinge 18 and rearwardly of the parting line 32, i.e. between the press bed 14 and the parting line 32.

Die blocks 24 are xedly mounted to each of the first pair of die support members and die blocks 25 are slidably mounted on the second pair of die support members. The reason for the slidable mounting of the die blocks on the second pair of die support members will become apparent in a more detailed explanation later.

Resilient mountings, e.g., springs, are applied to the transverse pivots of the rst and second pairs of die support members as well as the slidable die blocks of the second pair of die support members.

The pivotal mountings 15 of the first pair of die support members 16 are adapted to slide back and forth within the carriage 28 las the bending cycle progresses. A cross-section through carriage 28 as viewed from the side, as in FIG. 4, appears as an inverted E having top, bottom and intermediate legs outstanding. Slots 50, best seen in FIGS. 1-3, provide a guide for the longitudinal back land forth movement of the pivotal mountings 15. The mounting 15 in the form of a shouldered pin passes through the slots 50 in the legs of the carriage 28. Bearing blocks 51 support and guide the pin in the slots 50. 'I'he top bearing block rests on the shoulder of the pin. The intermediate bearing block rests on eye bolt 52 which connects mounting pin 15 to tension spring 21. The lower end of the pin passes through the lower bearing block which guides the pin in the bottom slot and rests on the inside of the bottom plate of housing 11 where lubrication is provided to aid the sliding action. The carriage 28 is thus free fioating within the housing 11. Pivotal mountings 15 connect the die blocks 16 to the carriage 28, the die blocks being guided in the housing 11 by pins 39 in guide slots 38 and 38. The carriage 28 is mounted within the first housing 11 and is designed to embrace the fixed nose block 22 in sliding engagement. Carriage 28 is provided with openings 40 and 40' to allow nose block 22 to pass therethrough. As the nose block moves past the parting line 32 the first pair of die support members 16 will pivot around their mountings 15. The mountings 15 are moved longitudinally towards each other against tension springs 21 which urge them back to their initial positions |at the end of the operation. Means, i.e. guide slots 38 and 38 provided in housing 11 together with guide pins 39' protruding from the die support members 16 guide said die support Imembers in a predetermined path to insure the abutting relationship of die blocks 24, fixedly mounted on the first pair of die support members 16, with the tip of nose blocks 31. Similar guide slots and pins are provided in housing 12 to guide die support members 17.

Adjustable means in the form of shim stacks is provided lat the back of the first housing 11 to limit the movement of the first pair of die support members 16, relative to the ram 13 and the nose block 22 affixed thereto. The shim plates 20 are manually inserted through openings 41 in housing 11. It is obvious that the simple process of adding to 0r removing from the shim stacks will provide adequate means for adjustment to a wide variety of sizes of members and desired angles of bend.

The transverse pivots 19 of the second pair of die suport members are mounted on rollers 23 at the back of the fixed housing 12 and are adapted to be moved longitudinally away from each other against compression springs 29 as the nose block moves past the parting line blocks. The compression springs return the die blocks to their starting position as the bending pressure is released.

Die blocks 25 are slidably mounted on said second pair of die support members 17 as mentioned heretofore. Referring now to FIGS. 2 and 3, it is evident that when the nose block 22 of said first housing together with the workpiece contacts the die blocks 25 the workpiece will be firmly engaged between the first and second pairs of die blocks. During the bending cycle the portions of the workpiece bearing on the die blocks 25 are deflected, and to freely permit this, and to prevent binding or scraping of the workpiece over the die blocks 25, the die blocks 25 are adapted to slide in recesses provided in the support members 17, thus permitting movement of the die blocks with the workpiece. Compression springs 26 are provided for normally infiuencing the sliding die blocks toward each other.

In operation, referring to FIGS. 3 and 4, the pictured embodiment shows a workpiece 27, in this case a structural langle, which has been suitably heated in the area of the desired bend and placed between the die blocks so that one flange is horizontal and the other fiange is vertical. The die blocks are then brought together by the actuation of the hydraulic cylinder of the press ram 13 toward the fixed housing 12. The first housing 11 mounted on the movable press ram 13 fmoves toward the second housing 12 which is fixed on the press bed 14, the nose block 22 on the first housing 11 causing the bending of the workpiece 27 while the opposing die blocks 24 and 25 by virtue of their unique design and arrangement are held in clamping engagement with the workpiece 27 and deflect to the desired angle of bend.

The tendency of the horizontal flange to buckle or Warp in the area of bending is overcome by the clamping effect of the buckle lock bar assembly 30 which produces vertical pressure on the bending area and maintains the flange substantially fiat. The cam follower 35 which is mounted on the centerline of the press ram 13 on the first housing 11 engages the buckle lock bar 30 to exert increasing pressure on the cover block 34, as seen in FIG. 4, and thus on the workpiece 27 as the bending cycle progresses. The effect of this pressure on the heated area of the workpiece is to preserve the cross-section of the member and prevent distortion thereto by buckling or warping. Removable tong plates 36 are mounted on the nose block 22 and are adapted to preserve the shape of the outstanding leg of the workpiece.

The rotation of the die support members about their respective axes which are rearward of the parting line and outward from the center of the machine combined with the effect of the several springs 21, 26 and 29 assure clamping engagement with the workpiece while the nose block moves forward on the ram with suicient force to produce Ithe bend. The pivot points 15 of the first pair of die support members 16 with carriage 28 following a path established by guide slots 38 and 38' as the housing 11 is moved forward. This movement of the pivot points of first pair of die support members is limited by the engagement of carriage 28 with the shim stack 20. When the limit of the bend is reached, the hydraulic cylinder is withdrawn and the die support members returned to their starting positions by virtue of the resilient mountings.

It is readily observed that structural angles can be bent with the outstanding leg in compression, as pictured, or in tension by reversing the direction of the outstanding leg. Cover 4blocks 33 and 34 are adapted to be moved vertically so that the outstanding leg of the structural angle can be reversed, as seen in the dotted lines in FIG. 4. It is also readily understood that by the simple means of attaching die blocks of desired shape to the die support members other shapes such as channels, I-beams, strips, bars and similar objects as well as double tension land double compression bends in angles can also be bent in the machine of this invention.

The instant invention provides a positive means for controlling the bending of a variety of structural members to a desired shape without distortion while preserving the cross-section of structural members and insuring the same uniform accurate bend in successively bent members. The invention further provides a fast productive bending operation adapted to rapid change over from one bending operation to another and by virtue of the adjustable means for limiting the bend requires no special skill or feel on the part of the operator.

What is claimed is: 1. A bending tool for operation by a press including a ram and =a bed, comprising:

(a) a first housing and a second housing mounted respectively on the ram and the bed of the press and defining a parting line therebetween,

(b) a nose block mounted on said ram at the center thereof and extending towards said parting line, (c) a first pair of die support members carried in said first housing on opposite sides of said nose block and in abutting relationship thereto,

(d) transverse pivots mounting said iirst pair of die support members in said first housing for rotation about axes spaced outwardly of the nose block and rearwardly of the parting line,

(e) a second pair of die support members carried in said second housing at the center thereof, said second pair of die support members being connected to each other by a transverse hinge,

(f) transverse pivots mounting said second pair of die support members in said second housing for rotation about axes spaced outwardly of the hinge and References Cited rearwardly of the parting line, and OTHER REFERENCES (g) a pair of dies mounted for slidable longitudinal movement on said second pair of die support mem- 2,702578 2/1955 Hofn'an 72-389 bers. 3,021,886 2/1962 Ferns 72-389 2. The apparatus according to claim 1, including: 5 310941159 6/1963 Walsh 72-389 means for varying the limits of movement of said rst pair of die support members relative to said nose CHARLES W' LANHAM Pnmary Exammer block. G. P. CROSBY, Assistant Examiner 

